1. Field of the Art
The invention relates to an apparatus for sampling a section of tube in a nuclear fuel assembly of the type comprising a skeleton having two end-pieces and a plurality of grids distributed between the end-pieces along the tubes and arranged to retain a bundle of fuel elements between the end-pieces.
2. Prior Art
Most fuel assemblies of the above type used at the present time comprise tubes which constitute guides for rods of a control cluster. Each tube is fixed to the lower end-piece by a screw and to the upper end-piece by a sleeve crimped in the end-piece and projecting through the upper grid. It is often desirable to sample a section of the connecting structure between the tube and the upper end-piece to perform a corrosion examination on the sample providing an indication on the condition of the assembly skeleton.
At the present time, sampling is carried out generally upon complete dismantling of the assembly. To separate the upper end-piece from the tubes, a cutting tool is used which may be of various types inserted within the tube for sectioning it from inside. The tool may be as described in French No. 2,416,760. Processes and apparatus for completely dismantling fuel assembllies are also known (French No. 2,499,296).